At present, time and effort are being spent within the pulp and paper industry in studying ways and means of substantially reducing the high and still escalating cost of harvesting and preparing wood for delivery to the processing mill. Also, time and effort are spent in reducing the cost of producing energy. Therefore, all means capable of serving as a source of energy must be preserved. Every component of a tree may serve some purpose; it is therefore important that one hundred percent of a felled tree must be used. The limb debris of a cut tree can be used as a source of energy or, through a series of wood treating processes, can be converted into useful products.
Present tree delimbing methods are carried out directly at the cutting location and branches and leaves are left on the ground. One method of delimbing trees is described in Canadian Pat. No. 964,965 issued Mar. 25, 1975 to Michael Stadnick; this patent describes a truck carrying a rotating drum with flails which is driven over a pile of cut trees laying on the ground so that the rotating flails may engage and detach the branches and leaves. Since the tree delimber travels on felled timber, it is extremely difficult to obtain a complete delimbing of the trunk as the branches located between the trunk and the ground are not usually reached. Another type of tree delimber is described in Canadian Pat. No. 598,362 issued May 17, 1960 to David C. Horncastle. In this construction, trees are conveyed, one at a time, between two vertically disposed flail-carrying drums and the limb debris are expelled sideways on opposite side of the apparatus. During the operation of the apparatus of this patent, only one tree may be passed between the two adjacently disposed drums; hence, this construction is not recommended on cutting sites where a considerable number of cut trees must be quickly delimbed.